import javax.swing.tree.TreeNode;
class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode() {}
 *     TreeNode(int val) { this.val = val; }
 *     TreeNode(int val, TreeNode left, TreeNode right) {
 *         this.val = val;
 *         this.left = left;
 *         this.right = right;
 *     }
 * }
public class Solution1 {
        private boolean isSameTree(TreeNode p, TreeNode q) {
            if (p == null && q == null){
                return true;
            }
            if(p != null && q ==null || p == null && q!= null){
                return false;
            }
            if (p.val != q.val){
                return false;
            }
            return isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
        }

        public boolean isSubtree(TreeNode root, TreeNode subRoot){
            if (root == null || subRoot == null){
                return false;
            }
            if (isSameTree(root,subRoot)){
                return true;
            }
            if (isSubtree(root.left,subRoot)){
                return true;
            }
            if (isSubtree(root.right,subRoot)){
                return true;
            }
            return false;
        }
}


